1. Field of the Invention
The present invention relates to a transmitter, a receiver, a multi-class multimedia broadcast/multicast service system and modulation method thereof, and more particularly to a transmitter, a receiver, a multi-class multimedia broadcast/multicast service system and modulation method thereof for transmitting multi-class or multi-resolution data.
2. Description of the Prior Art
With enhancement in available bandwidth per user due to rapid development of mobile communication systems, demand for multimedia streaming services has been dramatically increased. Multimedia broadcast/multicast service (MBMS) system, which provides unidirectional point-to-multipoint service supporting data streams with different resolutions, has been proposed. The MBMS system is capable of eliminating bandwidth consumption by sharing radio resources and simultaneously providing desired services for a plurality of users.
However, streams with different resolutions are regarded as separate services in conventional MBMS systems and transmitted via independent radio resources, resulting in degradation in receiving efficiency. Therefore, it is now a current goal to achieve an improved overall system throughput, service coverage and signal-receiving quality.